Process of producing engraving-machine patterns.



UNITED STATES PATENT OFFICE.

MARK BARR, OF BROADHEATH, ENGLAND, ASSIGNOR TO THE LINOTYPE COMPANY, LIMITED, OF LONDON, ENGLAND.

PROCESS OF PRODUCING ENGRAVING-MACHINE PATTERNS.

SPECIFICATION forming part of Letters Patent,No. 669,973, dated March 19, 1901. Application led .August `14, 1899 Serial No. 727,136. (No specimens.)

To all whom, it may concern:

Be it known that I, MARK BARR, of Broadheat-h, in the county of Ohester, England, have invented a certain new and useful Process of Producing Engraving-Machine Patterns; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention consists in an improved process for the production of engraving-machine patterns. Y

Referring to the accompanying figures, which are to be taken as part of this specification and read therewith, Figure l is a perspective view of the two metal plates and the foil; Fig. 2, a side elevation of the same two plates soldered together; Fig. 3, a perspective view of the finished pattern and the bottom plate to which it is held, and Fig. 4 a side elevation corresponding therewith.

tis the pattern for use on the table of a pant/ograph or other engraving-machine under the tracer thereof. It is cut out of a metal plate along the proper outline and held fast upon a flat metal plateuof a larger area, the pattern t then standing cameowise or in basrelief upon the larger plate u. Any suitable metal may be used for either plate. I-Iardrolled brassgives satisfactory results. In carrying this invention into effect the top plate o, out of which the pattern tis to be cut, is fastened down upon the plate u. For convenience the plate o is of the same area as the plate u, as showin in Fig. l. This fastening down is effected by means of a solder or other fusible adhesive material having a melting-point below that of the metal of the plates u and o. The fastening agent is applied, preferably, in the form of a foil tu, because it is easier to get the agent laid evenly over either plate when it is in that form than it is by spreading it over the said plate piecemeal, as by a soldering-bit or by a brush. The foil w is of the same area as the plates u v, as shown in Fig. 1. The term foil is hereinafter to be understood as including any solder or fusible adhesive material. The thickness of the foil w may be as desired; but it is preferred that it should be as thin as is consistent with strong adhesion between the plates u and o. The said foil having been placed between the two plates u and t; with the edges of the three registering with each other, as indicated in Fig. 2, pressure and heat are applied to them sim ultaneously. The heat must be intense enough to melt the foil w. It is preferred that the two plates u t; and foil w shall be pressed together in a press and heat applied to them all three while they are in that position. The melting of the foil w, supplemented by the pressure, fastens the two plates fu, and c together. The plates u. and v and foil w are then cooled. If they had been raised to a high temperature, the cooling is effected at such a rate as will make the plate t) soft for being cut by the engraving-tool. The latter is set to cut through the plate tu and the foil w and may be set to cut through them both and for a short distance into the plate u, it being guided in so cutting by the travel of the tracer over the original. When the cutting has been completed, the plates fu and u, still fast together and having the pattern separated from the rest of the plate t by the groove made by the engraving-tool, are taken off the work-table of the engravingmachine and are further fixed together by means of rivets m, passed through them both, or by equivalent means. The :foil tu is then melted, whereby the unriveted portions of the plate v are detached from the plate fu, and are removed, leaving the pattern t in bas-relief thereupon, as illustrated in Figs. 3 and 4..

The hereinbeforedescribed process for pro- .ducing engraving-machine patterns, consisting of fastening two plates together bya foil pressure and heat; cutting a groove down through one according to the original; fixing the pattern to the bottom plate; and detaching the uniixed portions of the top plate from the bottom plate by melting the foil between them.

In testimony that I claim the foregoing as my invention I have signed my name in presence of two subscribing Witnesses.

MARK BARR.

Witnesses:

C. W. CARPE, H. A. WARNER. 

